Un/Installing Themes on o2 Pre

Hey guys, new member here... was tempted in by the Palm Pre themes you were offering so created myself an account and got stuck in
So, stupidly I managed to read all of the 'How to install themes' guide WITHOUT registering that I wasn't meant to install themes until a few days after an update... just 15mins before I had completed the most recent update to the GSM pre (which I gather has been in the US for a while...)
Anyway, I installed the theme and it did come up with a few errors (Error 5, if I remember correctly, though I don't remember reading what it said...)
Anyway... My touchscreen has been faulty for a while now and I'm sending it to be repaired tomorrow, but will installing the theme have any effect on the warranty/insurance? It's a hardware fault, so I'm doubtful, but to be on the safe side I tried to uninstall the theme from my pre. Problem! The option for 'revert to default theme' was greyed out and un-selectable...
Can you guys help?
Thanks,
Phil